Disk cartridge

ABSTRACT

A disk cartridge has a case including a first planar portion and a second planar portion which are disposed opposite to each other with a given spacing therebetween, and a plurality of walls which join the first planar portion and the second planar portion together. The case contains an information carrying disk in a rotatable manner and has an opening formed in one of the walls through which the disk can be inserted or removed. The disk cartridge has a lid mounted on the case for opening or closing the opening. The lid is formed so that an outer surface of the lid is located inside an outer surface of the wall in which the opening is formed.

BACKGROUND OF THE INVENTION

The present invention relates to a disk cartridge which contains aninformation carrying disk such as an optical disk or a magneto-opticaldisk in a manner to permit its insertion and removal.

A conventional disk cartridge which is commercially available in thetrade name of “electronic book” is illustrated in FIG. 34 to FIG. 38.Specifically, FIG. 34 is a plan view of an upper side of the diskcartridge (corresponding to A-side of the disk), FIG. 35 is a plan viewof the upper side, illustrating the manner of opening a shutter of thedisk cartridge shown in FIG. 34, and FIG. 36 is a plan view of a lowerside (corresponding to B-side of the disk), illustrating the manner ofopening the shutter of the disk cartridge shown in FIG. 34. Further,FIG. 37 is a cross section of the disk cartridge shown in FIG. 34 takenalong the line S₃₇—S₃₇ shown in FIG. 34, and FIG. 38 is a plan viewillustrating a manner of removing the disk from the disk cartridge shownin FIG. 34 by opening a lid of the cartridge.

As shown in FIG. 34 to FIG. 38, a conventional disk cartridge includes acase 1 which contains a disk 5 in a rotatable manner. The case 1includes an upper member 2 and a lower member 3 which are disposedopposite to each other with a given spacing therebetween to define aspace 4 in which the disk 5 is received. The upper member 2 includes anupper planar portion 6 of the case 1, and a part of the walls 7, 8, 9and 10 of the case 1, which substantially correspond to one-halfthereof. Similarly, the lower member 3 includes a lower planar portion11 of the case 1, and a part of the walls 7, 8, 9 and 10 of the case 1,which substantially correspond to one-half thereof.

The upper member 2 is provided with a window 2 a through whichinformation is written into or read from the A-side of the disk 5.Similarly, the lower member 3 is provided with a window 3 a throughwhich information is written into or read from the B-side of the disk 5.The case 1 is also provided with a shutter 12 which opens or closes thewindows 2 a and 3 a.

The wall 10 of the case 1 is formed with an opening 13 which permits thedisk 5 to be inserted into or removed from the case 1. The case 1 isprovided with a lid 14 which opens or closes the opening 13. The lid 14is supported by the case 1 so as to be pivotable about a pivot 15 in aplane parallel to the upper and the lower planar portions 6 and 11 ofthe upper and the lower members 2 and 3.

In the conventional disk cartridge as mentioned, the lid 14 is formedwith an end face 14 a which is located on the outside of the end faces 2b and 3 b of the upper and the lower members 2 and 3 so as to coverthese end faces 2 b and 3 b. Accordingly, when a locking mechanism forthe lid 14 (not shown in FIG. 34 to FIG. 38) is unlocked to open the lid14, there is a likelihood that undue forces may be applied to the lid 14to cause a plastic deformation thereof, thereby degrading the accuracyof the end face 14 a of the lid 14. Also, when the lid 14 is closed, ifthe lid 14 is locked imperfectly, the end face 14 a which is urged by ahand assembly of a disk changer mechanism (not shown in FIG. 34 to FIG.38) assumes a slant position, again degrading the accuracy. Accordingly,in either instance, when the hand assembly of the disk changer mechanismpresses the end face 14 a of the lid 14 to move the disk cartridge intoa record/playback unit, the disk cartridge may be forcibly insertedwhile the disk cartridge assumes the slant position. In worst cases, thedisk cartridge may be jammed within the record/playback unit to disableeither insertion or removal of the disk cartridge.

In addition, there is a problem that when removing the disk 5 from thedisk cartridge, the information carrying surface of the disk 5 may comeinto contact with the end faces 2 b and 3 b or the internal surfaces ofthe upper and the lower members 2 and 3, whereby the informationcarrying surface of the disk 5 may be scarred.

In addition, when inserting the disk 5 into the disk cartridge, dustwhich is electrostatically attracted or hand-grease may be depositedupon the information carrying surface of the disk 5, interfering with orpreventing read-out of the information from the disk 5.

The absence of a mechanism which guides the disk 5 when it is to bereceived within the disk cartridge may cause the disk 5 to be dropped inthe course of containing it into the disk cartridge, or cause theinformation carrying surface of the disk 5 to be brought into contactwith the internal surfaces of the case 1, or cause a deposition of thehand-grease or the like upon the information carrying surface of thedisk 5.

Also absent is a mechanism which detects whether the disk 5 has neverbeen removed from the disk cartridge or whether it has been removed atleast once. Accordingly, when it is desired to record information, anoperation to distinguish whether or not a normal recording operation ispossible or an operation to verify the format of the disk 5 must beexecuted before a record operation can be initiated, increasing thelength of time required for the record operation.

Finally, the opening 13 of the disk cartridge is of a size which permitsa plurality of varieties of disks such as MD (trade name: mini-disk) ordisk used as an electronic book to be directly inserted into the diskcartridge, presenting a problem that a different type of disk other thanintended may be inadvertently inserted into the disk cartridge.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a diskcartridge which allows a disk changer mechanism to move a disk into arecord/playback unit in a proper stabilized position in the event a lidundergoes a plastic deformation.

It is another object of the present invention to provide a diskcartridge which eliminates the likelihood of scarring an informationcarrying surface of the disk during the insertion or the removal of thedisk.

It is still another object of the present invention to provide a diskcartridge which is capable of removing deposited dust or marring bygrease on the disk which is inserted into the disk cartridge.

It is a yet another object of present invention to provide a diskcartridge which eliminates the need to hold the disk by hand during theinsertion of the disk into the disk cartridge.

It is a further object of the present invention to provide a diskcartridge which enables the detection of whether the disk has ever beenremoved from the disk cartridge or whether it has been removed at leastonce, thereby allowing the length of time required for the informationrecording operation to be reduced.

It is a still further object of the present invention to provide a diskcartridge which prevents the insertion of the disk having a differentconfiguration.

According to one aspect of the present invention, a disk cartridge has acase including a first planar portion and a second planar portion whichare disposed opposite to each other with a given spacing therebetween,and a plurality of walls which join the first planar portion and thesecond planar portion together, the case containing an informationcarrying disk in a rotatable manner and having an opening formed in oneof the walls through which the disk can be inserted or removed; and alid mounted on the case for opening or closing the opening, the lidbeing formed so that an outer surface of the lid is located inside anouter surface of the wall in which the opening is formed.

According to another aspect of the present invention, a disk cartridgehas a case including a first planar portion and a second planar portionwhich are disposed opposite to each other with a given spacingtherebetween, and a plurality of walls which join the first planarportion and the second planar portion together, the case containing aninformation carrying disk in a rotatable manner and having opening inone of the walls through which the disk can be inserted or removed; alid mounted on the case for opening or closing the opening; and at leasttwo projections formed on an outer surface of the lid and having anequal height, the outer surface of the lid being parallel to the wall inwhich the opening is formed.

According to a still another aspect of the present invention, a diskcartridge has a case including a first planar portion and a secondplanar portion which are disposed opposite to each other with a givenspacing therebetween, and a plurality of walls which join the firstplanar portion and the second planar portion together, the casecontaining a disk, which has an annular first projection adjacent to anouter periphery of the disk on an information carrying surface of thedisk, in a rotatable manner; and a second projection formed on at leastone of internal surfaces of the first planar portion and the secondplanar portion in a region located opposite to the first projection andadapted to abut against the first projection.

According to a yet another aspect of the present invention, a diskcartridge has a case including a first planar portion and a secondplanar portion which are disposed opposite to each other with a givenspacing therebetween, and a plurality of walls which join the firstplanar portion and the second planar portion together, the casecontaining an information carrying disk in a rotatable manner and havingan opening formed in one of the walls through which the disk can beinserted or removed; a lid mounted on the case for opening or closingthe opening; and a cleaning member mounted on at least one of internalsurfaces of the first planar portion and the second planar portion so asto face an information carrying surface of the disk, thereby being incontact with the information carrying surface of the disk when the diskis inserted into or removed from the case.

According to a further aspect of the present invention, a disk cartridgehas a case including a first planar portion and a second planar portionwhich are disposed opposite to each other with a given spacingtherebetween, and a plurality of walls which join the first planarportion and the second planar portion together, the case containing aninformation carrying disk in a rotatable manner and having an openingformed in one of the walls through which the disk can be inserted orremoved; a lid mounted on the case for opening or closing the opening;support means for supporting the lid so as to be capable of rotating ina plane parallel to the first planar portion and the second planarportion; and a holding groove formed inside the lid to permit an outerperiphery of the disk to be fitted therein.

According to a still another aspect of the present invention, a diskcartridge has a case including a first planar portion and a secondplanar portion which are disposed opposite to each other with a givenspacing therebetween, and a plurality of walls which join the firstplanar portion and the second planar portion together, the casecontaining an information carrying disk in a rotatable manner and havingan opening formed in one of the walls through which the disk can beinserted or removed; a lid mounted on the case for opening or closingthe opening; a penetration formed in the second planar portion; aprojection projecting from an inside of the case and having a smallerdiameter than the penetration; and a recess formed in the lid forengaging the projection when the lid is closed and operable to sever theprojection when the lid is opened, thereby causing the projection to bedischarged outside the case through the penetration.

According to another aspect of the present invention, a disk cartridgehas a case including a first planar portion and a second planar portionwhich are disposed opposite to each other with a given spacingtherebetween, and a plurality of walls which join the first planarportion and the second planar portion together, the case containing aninformation carrying disk in a rotatable manner and having an openingformed in one of the walls through which the disk can be inserted orremoved; a lid mounted on the case for opening or closing the opening;and an insertion restriction part projecting from at least one ofinternal surfaces of the first planar portion and the second planarportion for reducing a width of the opening substantially equal to athickness of the disk in a range which does not interfere with aninsertion or removal of the disk.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1A is a plan view of an upper surface of a disk cartridge accordingto a first embodiment of the present invention, corresponding to anA-side of the disk;

FIGS. 1B-1D are side elevations of a left, a right and a front wall ofthe disk cartridge shown in FIG. 1A;

FIG. 2 is a cross section of the disk cartridge shown in FIG. 1A takenalong the line S₂—S₂;

FIG. 3 is a plan view of the disk cartridge shown in FIG. 1A with ashutter open;

FIG. 4 is a plan view of the disk cartridge when a lid associated withan opening through which the disk is inserted or removed is closed;

FIG. 5 is a fragmentary enlarged view of an area indicated by a symbol Ain FIG. 4;

FIG. 6 is a plan view of the disk cartridge of the first embodiment whena lid associated with the opening is opened;

FIG. 7A is a plan view of an upper surface of a disk cartridge accordingto a second embodiment of the present invention, corresponding to anA-side of the disk;

FIGS. 7B-7D are side elevations of a left, a right and a front wall ofthe disk cartridge shown in FIG. 7A:

FIG. 8 is a cross section of the disk cartridge shown in FIG. 7A takenalong the line S₈—S₈;

FIG. 9 is a cross section of the disk cartridge of the second embodimentwhen the lid associated with the opening is opened;

FIG. 10 is a plan view of the disk cartridge shown in FIG. 7A when theshutter is opened;

FIG. 11 is a fragmentary enlarged view of an area indicated by a symbolB in FIG. 8;

FIG. 12A is a plan view of a upper surface of a disk cartridge accordingto a third embodiment of the present invention, corresponding to anA-side of a disk;

FIGS. 12B-12D are side elevations of a left, a right and a front wall ofthe disk cartridge shown in FIG. 12A;

FIG. 13 is a cross section of the disk cartridge shown in FIG. 12A takenalong the line S₁₃—S₁₃;

FIG. 14 is a fragmentary enlarged view of an area indicated by a symbolC in FIG. 13;

FIG. 15 is a plan view of the disk cartridge of the third embodimentwhen the lid associated with the opening is opened;

FIG. 16 is a side elevation of the disk cartridge shown in FIG. 15 whenthe shutter is opened;

FIG. 17A is a plan view of an upper surface of a disk cartridgeaccording to a fourth embodiment of the present invention, correspondingto an A-side of a disk;

FIGS. 17B-17D are side elevations of a left, a right and a upper wall ofthe disk cartridge shown in FIG. 17A;

FIG. 18 is a cross section of the disk cartridge shown in FIG. 17A takenalong the line S₁₈—S₁₈;

FIG. 19 is a plan view schematically illustrating the configuration of adisk cartridge according to a fifth embodiment of the present invention;

FIG. 20 is a cross section of the disk cartridge shown in FIG. 19 takenalong the line S₂₀—S₂₀;

FIG. 21 is an enlarged cross section of an area indicated by a symbol Din FIG. 20;

FIG. 22 is a plan view schematically illustrating the configuration of adisk cartridge according to a sixth embodiment of the present invention;

FIG. 23 is an enlarged cross section of the disk cartridge shown FIG. 22taken along the line S₂₃—S₂₃;

FIG. 24 is a plan view schematically illustrating the configuration of adisk cartridge according to a seventh embodiment of the presentinvention;

FIG. 25 is an enlarged cross section of the disk cartridge shown in FIG.24 taken along the line S₂₅—S₂₅;

FIG. 26 is a plan view schematically illustrating the configuration of adisk cartridge according to an eighth embodiment of the presentinvention, when a lid is closed;

FIG. 27 Is a plan view schematically illustrating the configuration ofthe disk cartridge shown in FIG. 26 when the lid is opened;

FIG. 28 is an enlarged cross section of the disk cartridge shown in FIG.26 taken along the line S₂₈—S₂₈;

FIG. 29 is an enlarged cross section illustrating a condition in whichthe lid is once opened and is then closed;

FIG. 30 is a cross section schematically illustrating the configurationof a disk cartridge according to a ninth embodiment of the presentinvention;

FIG. 31 is a side elevation illustrating a wall in which the diskcartridge of FIG. 30 is provided with an opening;

FIG. 32 is a side elevation of a modification of the ninth embodimentshown in FIG. 30 and FIG. 31;

FIG. 33 is a side elevation of another modification of the ninthembodiment;

FIG. 34 is a plan view of an upper side of a conventional disk cartridge(corresponding to an A-side of the disk);

FIG. 35 is a plan view of the upper side, illustrating a manner ofopening a shutter of the disk cartridge shown in FIG. 34;

FIG. 36 is a plan view of a lower side (corresponding to a B-side of thedisk), illustrating the manner of opening a shutter of the diskcartridge shown in FIG. 34;

FIG. 37 is a cross section of the disk cartridge shown in FIG. 34 takenalong the line S₃₇—S₃₇ shown in FIG. 34; and

FIG. 38 is a plan view illustrating a manner of removing the disk fromthe disk cartridge shown in FIG. 34 by opening the lid of the diskcartridge.

DETAILED DESCRIPTION OF THE INVENTION

Some embodiments of the present invention will be described withreference to the attached drawings.

First Embodiment

FIGS. 1A to 1D schematically illustrate the configuration of a diskcartridge according to a first embodiment of the present invention,wherein FIG. 1A is a plan view of an upper surface of the disk cartridgecorresponding to an A-side of the disk, and FIGS. 1B-1D are sideelevations of a left, a right and a front wall of the disk cartridgeshown in FIG. 1A. FIG. 2 is a cross section of the disk cartridge shownin FIG. 1A taken along the line S₂—S₂ shown in FIG. 1A, FIG. 3 is a planview of the disk cartridge shown in FIG. 1A with a shutter open, FIG. 4is a plan view of the disk cartridge when a lid associated with anopening through which the disk is inserted or removed is closed, FIG. 5is a fragmentary enlarged view of an area indicated by a symbol A inFIG. 4, and FIG. 6 is a plan view of the disk cartridge of the firstembodiment when a lid associated with the opening is opened.

Referring to FIGS. 1A-1D and FIG. 2 to FIG. 6, the disk cartridgeaccording to the first embodiment includes a case 1 which contains adisk 5 such as an optical disk or a magneto-optical disk in a rotatablemanner. The case 1 is formed of, for example, a plastic material, butmay be formed of different material such as metal as well.

The case 1 includes an upper member 2 and a lower member 3 which aredisposed opposite to each other with a given spacing therebetween todefine a space 4 in which the disk 5 is received. The upper member 2includes an upper planar portion 6 constituting an upper side of thecase 1, corresponding to the A-side of the disk 5, and a part ofsubstantially one-half of walls 7, 8, 9 and 10 forming the case 1.Similarly, the lower member 3 includes a lower planar portion 11constituting a lower side of the case 1, corresponding to the B-side ofthe disk 5, and a part of substantially one-half of the wall 7, 8, 9 and10 forming the case 1. The upper member 2 and the lower member 3 arebonded together by an adhesive, for example. However, it should beunderstood that the case 1 need not be formed of a pair of members suchas the upper member 2 and the lower member 3, but may be formed of threeof more members. Alternatively, the case 1 may be integrally formed froma single member.

The upper member 2 is provided with a window 2 a through whichinformation is written into or read from the A-side of the disk 5.Similarly, the lower member 3 is provided with a window 3 a throughwhich information is written into or read from the B-side of the disk 5.The case 1 is provided with a shutter 12 which opens or closes thewindows 2 a and 3 a. As shown in FIG. 2, the shutter 12 is substantiallyU-shaped. The shutter 12 is constructed with a metal, for example. Asshown in FIG. 1A and FIG. 3, the shutter 12 is mounted so as to beslidable with respect to the case 1.

The wall 10 of the case 1, or the end face of the case 1 which islocated opposite from the shutter 12 is formed with an opening 13through which disk 5 may be inserted or removed. In the firstembodiment, the wall 10 of the case 1 has an end face 2 b of the uppermember 2 and an end face 3 b of the lower member 3. It is to be notedthat the end face 2 b of the upper member 2 and the end face 3 b of thelower member 3 are disposed so as to be co-planar, or be aligned witheach other as viewed in FIGS. 1A, 1B and 1C.

Referring to FIG. 4 and FIG. 6, the case 1 is provided with a lid 16which opens or closes the opening 13. The lid 16 is supported on thecase 1 by means of a pivot 15 so as to be capable of pivotable motion ina plane parallel to the planar portions 6 and 11 in a region locatedbetween the upper planar portion 6 of the upper member 2 and the lowerplanar portion 11 of the lower member 3. The pivot 15 may have a pair ofprojections which are integrally formed on the opposite surfaces of thelid 16 and which are rotatably engaged with recesses, not shown, formedin the internal surfaces of the planar portion 6 of the upper member 2and the planar portion 11 of the lower member 13 adjacent to one cornerof the case 1. However, the construction of the pivot 15 is not limitedto the one just mentioned, and alternatively, the lid 16 may besupported by an engagement between the projections formed on theinternal surfaces of the planar portions 6 and 11, and recesses in theopposite surfaces of the lid 16. As a further alternative, the lid 16may be rotatably supported by a shaft, not shown, serving as the pivot15, which is fixedly mounted on the internal surfaces of the planarposition 6 of the upper member 2 and the planar portion 11 of the lowermember 3.

As shown in FIG. 4 to FIG. 6. the disk cartridge includes a lockingmechanism 17 which detains the lid 16 to the case 1 when the lid 16 isclosed. The locking mechanism 17 has a hole 9 a which is formed in thewall 9 of the case 1, and a projection 16 a formed on the lid 16 andengaging the hole 9 a when the lid 16 is closed. However, it should beunderstood that the construction of the locking mechanism 17 is notlimited to the precise construction mentioned above, but may comprise aprojection formed on the wall 9 of the case 1 and a recess formed in thelid 16.

As shown in FIGS. 1A-1D, FIG. 2, FIG. 4 and FIG. 5, in the diskcartridge according to the first embodiment, the outer surface 16 b ofthe lid 16 is formed so as to be located inside the outer surface of thewall 10 in which the opening 13 is formed when the lid 16 is closed.

With the disk cartridge constructed in a manner mentioned above, when itis desired to remove the disk 5 from the disk cartridge, the lockingmechanism 17 is unlocked as by pushing the projection 16 a of the lid 16from the outside of the hole 9 a using a tool having a pointed end, thuscausing the lid 16 to rotate about the pivot 15 and thus opening theopening 13 to allow the disk 5 to be removed. Conversely when the disk 5is to be inserted into the disk cartridge, the disk 5 is insertedthrough the opening 13 with the lid 16 maintained in its open condition,and then the lid 16 is rotated toward the case 1, followed by pushingthe lid 16 towards the case 1. Thereupon, the projection 16 a of the lid16 abuts against the end of the wall 9, and subsequently moves into thecase 1 while abutting against the internal surface of the wall 9 andwhile undergoing slight elastic deformation, which is eliminated byengaging the hole 9 a in the case 1.

When the described disk cartridge is to be used with a record/playbackunit, not shown, which is provided with a disk changer mechanism, anoperation which causes the disk cartridge to be loaded into the diskchanger mechanism to move into record/playback position takes place asfollows:

Referring to FIG. 2, a hand assembly 18 of the disk changer mechanism isbrought into abutment against the wall 10 of the case 1 of the diskcartridge, applying a force to the wall 10 acting in the directionindicated by an arrow, thus moving the disk cartridge. Thus, when thedisk cartridge of the first embodiment is brought to its record/playbackposition by means of the disk changer mechanism, the wall 10 of the case1 of the disk cartridge, which is defined by the combination of the endface 2 b of the upper member 2 and the end face 3 b of the lower member3, is pushed for movement.

As discussed, with the disk cartridge according to the first embodiment,the lid 16 is located between the upper member 2 and the lower member 3,and accordingly, no undue forces which would result from the opening andthe closing of the lid 16 cannot be directly applied to the end faces 2b and 3 b of these members 2 and 3, thus preventing the likelihood thata plastic deformation is caused to these end faces 2 b and 3 b. Hence,the relative position between the end faces 2 b and 3 b is maintainedconstant. In addition, since there is no chance that a deformation iscaused to the end faces 2 b and 3 b themselves, the accuracy of theseend faces 2 b and 3 b can be maintained intact from their initialcondition, whereby a contact with a pushing surface 18 a of the handassembly 18 can be maintained in a good condition. In this manner, withthe disk cartridge according to the first embodiment, an inconvenienceis prevented that the disk cartridge may be forcibly inserted into therecord/playback position with its leading edge (corresponding to its endface 8) either raised or lowered, causing a jamming within therecord/playback unit to make the insertion or removal of the diskcartridge impossible in worst cases.

In the event the locking operation by the locking mechanism 17 isimperfect when the lid 16 is closed, the hand assembly 18 pushes thewall 10 of the case 1 rather than the end face 16 b of the lid 16 sincethe end face 16 b of the lid 16 does not project beyond the wall 10 ofthe case 1 (or end faces 2 b and 3 b). Accordingly, with the diskcartridge according to the first embodiment, a slant position of thedisk cartridge which may result from the hand assembly 18 pressingagainst the lid 16 which assumes a half-open position can be preventedfrom occurring. In this manner, an inconvenience can be prevented thatthe disk cartridge be forcibly inserted into the record/playbackposition or it may become jammed within the record/playback unit todisable its insertion or its removal in worst cases.

Second Embodiment

FIGS. 7A-7D schematically illustrate the configuration of a diskcartridge according to a second embodiment of the present invention,wherein FIG. 7A is a plan view of an upper surface of the disk cartridgecorresponding to the A-side of the disk, and FIGS. 7B-7D are sideelevations of a left, a right and a front wall of the disk cartridgeshown in FIG. 7A. FIG. 8 is a cross section of the disk cartridge shownin FIG. 7A taken along the line S₈—S₈. FIG. 9 is a cross section of thedisk cartridge when the lid associated with the opening is opened, FIG.10 is a plan view of the disk cartridge shown in FIG. 7A when theshutter is opened, and FIG. 11 is a fragmentary enlarged view of an areaindicated by a symbol B in FIG. 8.

Throughout FIGS. 7A-7D, and FIG. 8 to FIG. 11, parts identical orcorresponding to those shown in the first embodiment are designated bythe same reference numerals or characters as used before.

Referring to FIGS. 7A-7D, and FIG. 8 to FIG. 11, the disk cartridgeaccording to the second embodiment differs from the disk cartridge ofthe first embodiment with respect to of the configuration of an opening21 formed in the case 1 and the construction of a lid 22 which opens orcloses the opening 21.

As best shown in FIG. 9 and FIG. 10, the opening 21 in the secondembodiment extends not only through the wall 10 of the case 1, but alsointo the planar portion 6 of the upper member 2.

In addition, in the disk cartridge of the second embodiment, a notch 23is formed at the center of the wall 10 of the lower member 3, while ahook 22 b is formed on the distal end of the lid 22 for engaging thenotch 23, as shown in FIG. 7D and FIG. 8 to FIG. 11. The combination ofthe hook 22 b and the notch 23 constitutes a locking mechanism 24 whichlocks the lid 22 in the case 1. However, it should be understood thatthe locking mechanism 24 is not limited to the described construction,but may have a different construction.

The lid 22 has an outer surface 22 c, which is located inside the outersurface of the wall 10 of the case 1 when the lid 22 is closed, as shownin FIG. 7A, FIG. 8 and FIG. 11.

With the disk cartridge constructed in the manner mentioned above, whenit is desired to remove the disk 5, the hook 22 b is pulled by a fingerto be disengaged from the notch 23, and the lid 22 may be rotated abouta pivot 22 a, thus opening the lid 22 to allow the disk 5 to be removed.Conversely, when it is desired to insert the disk 5 into the diskcartridge, the disk 5 is inserted through the opening 21 under thecondition that the lid 22 is opened, and then the lid 22 is turnedtowards the case 1, followed by pushing the lid 22 against the case 1from above. The hook 22 b of the lid 22 then abuts against the uppersurface of the notch 23 while undergoing a degree of elasticdeformation, which is eliminated when the hook 22 b has moved past thenotch 23, whereupon the lid 22 is engaged with the notch 23.

When the described disk cartridge is used in a record/playback unit (notshown) which is provided with a disk changer mechanism, the diskcartridge which is loaded into the disk changer mechanism may be broughtto a record/playback position, by disposing the hand assembly of thedisk changer mechanism in abutment against the wall 10 of the diskcartridge, and applying a force to the wall 10 to move the diskcartridge. Thus, when the disk cartridge of the second embodiment isbrought to the record/playback position by the disk changer mechanism,the wall 10 of the disk cartridge is pressed for movement.

With the disk cartridge of the second embodiment, undue forces cannot bedirectly applied to the end faces 2 b and 3 b of the upper and the lowermember 2 and 3 (or the wall 10) as a result of the opening or closing ofthe lid 22, and hence there is no likelihood that these end facesundergo a plastic deformations. Hence, the positional relationshipbetween the end faces 2 b and 3 b is maintained constant, and thesurface which is defined by the end faces 2B and 3B cannot undergo thedeformation, thus maintaining the accuracy of the surface defined by theend faces 2 b and 3 b intact as formed at the initial condition. Thisassures a good contact with the pushing surface of the hand assembly. Asa consequence, with a disk cartridge of the second embodiment, aninconvenience can be prevented that the disk cartridge may be forciblyinserted to bring it into record/playback position while it assumes aslant position or that it may be jammed within a record/playback unit todisable the insertion or the removal of the disk cartridge in worstcases.

Additionally, the disk cartridge of the second embodiment has theopening 21 which is formed to a greater size than the conventional one,as shown in FIG. 9 and FIG. 10, thus allowing the disk 5 to be insertedinto or to be removed from disk cartridge along an upwardly slant pathto facilitate the insertion or the removal of the disk 5. This alsoavoids the likelihood of bringing the disk 5 into contact with the endfaces 2 b and 3 b of the upper and the lower members 2 and 3 whenremoving the disk 5, thereby scarring the information carrying surfaceof the disk 5.

In other respects, the disk cartridge of the second embodiment is thesame as that of the first embodiment.

Third Embodiment

FIGS. 12A-12B schematically illustrate the configuration of a diskcartridge according to a third embodiment of the present invention,wherein FIG. 12A is a plan view of an upper surface of the diskcartridge corresponding to an A-side of the disk, and FIGS. 12B-12D areside elevations of a left, a right and a front wall of the diskcartridge shown in FIG. 12A. FIG. 13 is a cross section of the diskcartridge shown in FIG. 12A taken along the line S₁₃—S₁₃, FIG. 14 is afragmentary enlarged view of an area indicated by a symbol C in FIG. 13,FIG. 15 is a plan view of the disk cartridge when the lid associatedwith the opening is opened, and FIG. 16 is a side elevation of the diskcartridge shown in FIG. 15 when the shutter is opened.

Throughout FIGS. 12A-12D, and FIG. 13 to FIG. 16, parts identical orcorresponding to those shown in the first embodiment are designated bythe same reference numerals and characters as used before.

Referring to FIGS. 12A-12D, and FIG. 13 to FIG. 16, the disk cartridgeaccording to the third embodiment differs from that of the firstembodiment with respect to of the configuration of an opening 31 formedin the case 1 and the construction of a lid 32 which opens or closes theopening 31.

As best shown in FIG. 12A and FIG. 15, in the third embodiment, theopening 31 extends not only through the wall 10 of the case 1, but alsointo the planar portion 6 of the upper member 2.

In the third embodiment, a first rectilinear groove 33 is formed in theinternal surface of the lower member 3, as will be noted from FIG. 14and FIG. 16. A second rectilinear groove 34 is formed in the end face ofthe upper member 2 as will be noted from FIG. 14. A lid 32 is L-shaped,and has its one end engaged with the first rectilinear groove 33 formedin the lower member 3 and its other end engaged in the secondrectilinear groove 34 formed in the upper member 2. The lid 32 opens orcloses the opening 31 by sliding movement while maintaining itsengagement with the first and the second rectilinear grooves 33 and 34.

As shown in FIG. 15 and FIG. 16, a pair of first and secondhemispherical projections 35 and 36 are formed on the upper surface ofthe lid 32. A pair of first and second holes (or recesses) 37 and 38 areformed in the upper member 2. When the lid 32 is closed, the first andthe second projections 35 and 36 engage with the first and the secondholes 37 and 38, respectively. On the other hand, when the lid 32 isopened, the second projection 36 engages the first hole 37.

In addition, as shown in FIG. 12A, and FIG. 13 to FIG. 16, in the diskcartridge of the third embodiment, the lid 32 has an outer surface 32 awhich is located inside the outer surface of the wall 10 in which theopening 31 is formed.

With the disk cartridge constructed in the manner mentioned above, whenit is desired to remove the disk 5, the lid 32 is caused to slide alongthe first and the second rectilinear grooves 33 and 34 until the secondprojection 36 becomes engaged with the first hole 37, whereupon the disk5 can be removed through the opening 31. Conversely, when the disk 5 isto be inserted into the disk cartridge, the disk 5 is inserted throughthe opening 31 while the lid 32 is maintained in its open position, andthen the lid 32 is caused to slide along the first and the secondrectilinear grooves 33 and 34 until the first and the second projections35 and 36 become engaged with the first and the second holes 37 and 38,respectively.

When the disk cartridge is used with the record/playback unit (notshown) which is provided with disk changer mechanism, the disk cartridgewhich is loaded into the disk changer mechanism may be brought to itsrecord/playback position, by disposing a hand assembly of the diskchanger mechanism in abutment against the wall 10 of the disk cartridge,thereby applying a force to the wall 10 to move the disk cartridge.Thus, in the third embodiment, when the disk cartridge is moved to therecord/playback position by means of the disk changer mechanism, thehand assembly of this mechanism (not shown) presses against the wall 10of the disk cartridge for its movement.

In the third embodiment described above, undue forces which may resultfrom opening or closing the lid 32 cannot be directly applied to the endface 2 b of the upper member 2 and the end face 3 b of the lower member3 (namely, the wall 10), and hence, there is no likelihood that theseend faces 2 b and 3 b undergo a plastic deformation. Accordingly, thepositional relationship between the end faces 2 b and 3 b is maintainedconstant, and the surface which is defined by these end faces cannotundergo the deformation, whereby the accuracy of the surface defined bythese end faces 2 b and 3 b may be maintained intact as it is at theinitial condition. In addition, a good contact with a pushing surface ofthe hand assembly of the disk changer mechanism is maintained.Accordingly, with the disk cartridge according to the third embodiment,an inconvenience can be prevented that the disk cartridge may beforcibly inserted and brought to its record/playback position while itassumes a slant position or it may be jammed within the record/playbackunit to disable its insertion or removal in worst cases.

Finally, as shown in FIG. 15, the case of the disk cartridge accordingto the third embodiment has its opening 31 formed to be of a greatersize than the conventional one, thus allowing the disk 5 to be insertedor removed along an upwardly slant path, thus facilitating the insertionor the removal of the disk 5. Any likelihood that the disk may bebrought into contact with the end faces 2 b and 3 b of the upper and thelower member 2 and 3 to scar the information carrying surface of thedisk 5 is eliminated.

In other respects, the construction of the third embodiment is the sameas that of the first embodiment described above.

Fourth Embodiment

FIGS. 17A-17D schematically illustrate the configuration of a diskcartridge according to a fourth embodiment of the present invention,wherein FIG. 17A is a plan view of an upper surface of the diskcartridge corresponding to an A-side of the disk, and FIGS. 17B-17D areside elevations of a left, a right and a front wall of the diskcartridge shown in FIG. 17A.

Throughout FIGS. 17A-17D and FIG. 18, parts identical or correspondingto those used in the first embodiment are designated by the samereference numerals and characters as used before.

Referring to FIGS. 17A-17D and FIG. 18, the disk cartridge according tothe fourth embodiment differs from the disk cartridge of the firstembodiment with respect to the construction of a lid 42 which opens orcloses an opening 41 formed in the wall 10 of the case 1.

In the fourth embodiment, the disk cartridge includes the lid 42, whichis supported in a rotatable manner by a pivot 45 between the uppermember 2 and the lower member 3, in the same manner as in the firstembodiment. However, in the disk cartridge of the fourth embodiment, thelid 42 has an end face 42 a which is located outside the end faces 2 band 3 b of the upper and the lower members 2 and 3, and is formed so asto cover these end faces 2 b and 3 b. In addition, a pair of projections42 b and 42 c are formed on the end face 42 a of the lid 42. Theprojection 42 b is formed adjacent to the pivot 45 about which the lid42 is rotatable, namely, adjacent to a corner where the walls 7 and 10of the case 1 intersect with each other. The other projection 42 c isformed adjacent to another corner where the walls 9 and 10 of the case 1intersect with each other. It will be noted from FIG. 18 that theprojections 42 b and 42 c represent locations which are pressed by thehand assembly 18 of the disk changer mechanism when the disk cartridgeis inserted into a record/playback unit which is provide with a diskchanger mechanism. It is to be understood that the number of theprojections is not limited to two, but may be three or greater as longas any load applied by the hand assembly 18 cannot cause a deformationof the lid 47. It is desirable that the locations of the projections 42b and 42 c be chosen to allow a force applied from the hand assembly 18to be uniformly transmitted to the case 1.

In the disk cartridge of the fourth embodiment, the projections 42 b and42 c are formed on the lid 42 at the locations which are adjacent tocorners of the case 1 which are not susceptible to a plasticdeformation. Accordingly, if undue stresses are applied to the lid 42 tocause a plastic deformation to degrade the accuracy of the entire endface 42 a when the disk cartridge is unlocked to open the lid 42, it ispossible to maintain a constant positional relationship between theprojections 42 b and 42 c, and hence the accuracy of the surface definedby these projections. Accordingly, when the disk cartridge is used withthe disk changer mechanism to load the case 1 into place within arecord/playback unit, the accuracy of the surface defined by the pair ofprojections 42 b and 42 c can be maintained intact as it is at theinitial condition. Hence as this surface is pressed by the hand assembly18, it is assured that the disk cartridge can be normally loaded intothe record/playback unit.

In other respects, the construction of the fourth embodiment is the sameas that of the first embodiment.

Fifth Embodiment

FIG. 19 is a plan view schematically illustrating the configuration of adisk cartridge according to a fifth embodiment of the present invention,FIG. 20 is a cross section of the disk cartridge shown in FIG. 19 takenalong the line S₂₀—S₂₀, and FIG. 21 is an enlarged cross section of anarea indicated by a symbol D in FIG. 20.

Throughout FIG. 19 to FIG. 21, parts identical or corresponding to thoseshown in FIG. 34 to FIG. 38 (the conventional disk cartridge) aredesignated by the same reference numerals and characters as used before.

Referring to FIG. 19 to FIG. 21, the disk cartridge according to thefifth embodiment differs from the conventional arrangement shown in FIG.34 to FIG. 38, only with respect to the provision of rectilinearlyextending projections 51, 52, 53 and 54 formed on the internal surfacesof the upper member 2 and the lower member 3, respectively.

It is only necessary that the projections 51-54 be formed on theinternal surface or the surfaces of the case 1 in a region which isdisposed opposite to at least information carrying surface of the disk5. It is also desirable that a single projection has a length chosen sothat the projections abut against a projecting rim 5 c of the disk 5 attwo locations. The length is preferably greater than the diameter of thedisk 5. In the fifth embodiment, a pair of projections are formed on theinternal surface of each of the upper member 2 and the lower member 3.The purpose of these projections 51-54 is to prevent the informationcarrying surface of the disk 5 from being scarred during the insertionor the removal of the disk 5 into or from the case 1.

As illustrated in FIG. 21, the disk 5 such as an optical disk has anannular rim 5 c formed around its outer periphery which has a greaterelevation than the information carrying surface of the disk. The rim 5 cmay contact one or more of the projections 51-54 within the case 1during the insertion and removal of the disk 5, thus preventing theinformation carrying surface of the disk 5 from being brought intocontact with internal surface of the case 1 to be scarred thereby.

In the above description, the provision of the projections 51-54 hasbeen described in connection with the conventional arrangement shown inFIG. 34 to FIG. 38, but it should be understood that the provision ofsuch projections 51-54 is also applicable to any one of the first to thefourth embodiments mentioned above.

Sixth Embodiment

FIG. 22 is a plan view schematically illustrating the configuration of adisk cartridge according to a sixth embodiment of the present invention,and FIG. 23 is an enlarged cross section of the disk cartridge shownFIG. 22 taken along the line S₂₃—S₂₃.

Throughout FIG. 22 and FIG. 23, parts identical or corresponding tothose used in the conventional arrangement shown in FIG. 34 to FIG. 38are designated by the same numerals or characters as before.

Referring to FIG. 22 and FIG. 23, the disk cartridge according to thesixth embodiment differs from the conventional arrangement shown in FIG.34 to FIG. 38 only with respect to a brush 61 and/or 62, serving as acleaning member disposed on at least one of the internal surfaces of thecase 1 and directed towards the information carrying surface of the disk5 for contact with either surface of the disk 5 during the insertion ofthe disk 5 into the case 1 or during the removal of the disk 5 from thedisk 1. It is to be noted that the brush 61 and/or 62 is located to bekept out of contact with the disk 5 during the rotation thereof, but toassure its contact with the information carrying surface of the disk 5when the lid 42 is opened to remove the disk 5 or to insert the disk 5.

With a disk cartridge of the sixth embodiment, a contact of the brush 61and/or 62 with information carrying surface of the disk 5 enables themarring on the information carrying surface as caused by the depositionthereon of dust which is electrostatically attracted, hand-grease or thecigarette nicotine to be removed. Because the removal of the marringwhich is deposited on the information carrying surface takes place eachtime the disk 5 is removed and/or inserted, it will be seen that when adisk 5 which is removed from the case 1 is inserted into the case 1again, the information carrying surface of the disk 5 is maintained in aclean condition, thus minimizing the occurrence of an error during therecording or retrieval of information onto or from the informationcarrying surface.

It is to be noted that the brush 61 and/or 62 may be replaced by a wetcleaning member, which is more suitable when removing hand-grease orcigarette nicotine. A brush and a wet cleaning member may be used incombination, as required. When a brush-like cleaning member is used, itis necessary to choose the length and the rigidity of brush hair so thatthe presence of the brush does not interfere with the removal or theinsertion of the disk 5. Where a wet cleaning member is used, it isnecessary to chose the viscosity and the rigidity so as to avoidinterference with the removal and insertion of the disk 5.

While the above description has dealt with the application of thecleaning member to the conventional arrangement shown in FIG. 34 to FIG.38, it should be understood that such cleaning member is also applicableto any one of the first to the fifth embodiments.

Seventh Embodiment

FIG. 24 is a plan view schematically illustrating the configuration of adisk cartridge according to a seventh embodiment of the presentinvention, and FIG. 25 is an enlarged cross section of the diskcartridge shown in FIG. 24 taken along the line S₂₅—S₂₅.

Throughout FIG. 24 and FIG. 25, parts identical or corresponding tothose used in the conventional arrangement shown in FIG. 34 to FIG. 38are designated by the same reference numerals and characters as usedbefore.

Referring to FIG. 24 and FIG. 25, the disk cartridge according to theseventh embodiment includes a lid 71, which is formed around its innerperiphery with a clamping groove 72 capable of fitting the outerperiphery of the disk 5 therein. The clamping groove 72 has a widthwhich is greater than the thickness of the rim 5 c extending around theouter periphery of the disk 5.

When the disk 5 is to be received in the case 1, the disk 5 is fittedinto the clamping groove 72 initially, and then the lid 71 is closed.This allows the disk 5 to be contained in a space 4 defined within thecase 1 while being guided by the clamping groove 72. A minimum width ofthe clamping groove 72 is chosen to avoid its contact with the disk 5 ascontained within the case 1 if it is rotating with a surfaceoscillation. A maximum width of the clamping groove 72 is chosen toavoid a contact of the information carrying surface of the disk 5 whichis fitted in the clamping groove of 72 with the internal surface of thecase 1 as a result of rattling of the disk 5 when the lid 71 is closed.

By guiding the disk 5 by means of the clamping groove 72, the occurrenceof the disk 5 dropping in the course of inserting it into the case 1 canbe prevented. In addition, the contact of the information carryingsurface of the disk 5 with the internal surface of the case 1 isavoided. Deposition of hand-grease on the information carrying surfaceof the disk 5, which may occur as a result of holding the disk 5 by handin order to guide the disk 5, is also eliminated. In this manner, aninconvenience such as a failure of recording information or readinginformation onto or from the information carrying surface as a result ofa marring of the information carrying surface by grease or like can beprevented. While the above description deals with the application of theclamping groove to the conventional arrangement shown in FIG. 34 to FIG.38, it should be understood that the provision of the clamping groove isalso applicable to any one of the first to the sixth embodiment.

Eighth Embodiment

FIG. 26 is a plan view schematically illustrating the configuration of adisk cartridge according to an eighth embodiment of the presentinvention when a lid is closed, FIG. 27 is a plan view schematicallyillustrating the configuration of the disk cartridge shown in FIG. 26when the lid is opened, FIG. 28 Is an enlarged cross section of the diskcartridge shown in FIG. 26 taken along the line S₂₈—S₂₈, and FIG. 29 isan enlarged cross section illustrating a condition in which a lid isonce opened and is then closed.

Throughout FIG. 26 to FIG. 29, parts identical or corresponding to thoseused in the conventional arrangement shown in FIG. 34 to FIG. 38 aredesignated by the same reference numerals and characters as used before.

The disk cartridge according to the eighth embodiment differs from theconventional disk cartridge shown in FIG. 34 to FIG. 38 only withrespect to a detector which detects whether a lid 81 has ever beenopened.

Referring to FIG. 26 to FIG. 29, the disk cartridge includes a detectionaperture 82 formed to extent through the upper member 2. Anidentification tab 83 is formed on a lower member 3 at the locationwhich is disposed opposite to the detection aperture 82. A relieved part83 a is formed around the root of the identification tab 83 in order toavoid a reduction in the strength of the case 1. A lid 81 is formed witha notch 81 a in surrounding relationship. with the identification tab83.

During the manufacture of the disk cartridge, the identification tab 83connected to the lower member 3 is located within the notch 81 a formedin the lid 81, as shown in FIG. 28. By detecting the presence of theidentification tab 83 through the detection aperture 82, it is possibleto recognize that the lid 81 has never been opened since the purchase ofthe disk cartridge.

When it is attempted to open the lid 81 to remove the disk from the case1, the wall of the notch 81 a which is formed in the lid 81 strikes theidentification tab 83, which is then broken from its root. However, thesevered identification tab 83 remains held in the notch 81 a to move asthe lid 81 is rotated and then falls down to be discharged outside whenthe notch 81 a is brought to the outside of the case 1. Thus, theidentification tab 83, which is once broken and brought to the outsideof the case 1, cannot be returned to its original position, and cannotbe restored into a space 4 within the case 1.

As shown in FIG. 29, another detection aperture 84 is formed at thelocation where the identification tab 83 on the lower member 3 isoriginally provided, the aperture 84 extending through the lower member3. It will be noted that the detection aperture 84 is formed at thelocation aligned with the detection aperture 82 initially formed in theupper member 2. In this manner, where the identification tab 83 isbroken and removed, the detection apertures 82 and 84 are formed toextend through both the upper and the lower members 2 and 3. If the lid81 is closed again, the detection apertures 82 and 84 cannot be blocked,maintaining a continuously extending aperture.

When a light emitting element (not shown) is disposed on the side of theupper member 2 in a record/playback unit which is used to recordinformation on the disk contained in the disk cartridge which is loadedtherein while a light receiving elements (not shown) is disposed on theside of the lower member 3, it follows that a failure of detecting lightby the light receiving element indicates the presence of theidentification tab 83 which remains in place without being broken. Inother words, it can be detected that the lid 81 has never been opened inthe disk cartridge which is loaded. However, if the light receivingelements detects light, this indicates that the light identification tab83 has been broken, forming a detection aperture 84. In other words, thelid 81 of the loaded disk cartridge has been opened at least once. Inthis manner, the record/playback unit is capable of detecting whetherthe disk has never been removed from the case 1 or has been removedtherefrom at least once.

When recording information on the disk which has been removed from thecase 1 at least once, it is necessary to verify the format of the diskin order to determine whether a normal recording operation is possiblewith the disk which is contained within the disk cartridge. If atechnique is employed to apply a record to the disk indicating a historyof removal from the case 1 and to read such record in order to determinethe need to verify the format by reading information which is oncerecorded on the disk, it will be seen that a length of time is requiredbefore a record operation can be initiated. However, if the detectionapertures 82 and 84 are formed which continue from one to the other ofthe members when the identification tab 83 is used according to thepresent invention, the need to verify the format is immediatelydetermined upon loading the disk cartridge in the record/playback unit,thus eliminating or minimizing the length of time required before therecord operation can be initiated. In this manner, a length of timerequired to complete the record operation can be reduced.

It will be noted that in place of the construction shown in FIG. 26 toFIG. 29, any construction can be used for the identification tab 83which can be broken from its root with a force of a magnitude which isproduced when opening the lid 81 by hand, such as a thin pin which isnot provided with a relieved fillet.

While the above description deals with the use of the detection apertureand identification tab 83 in the conventional arrangement shown in FIG.34 to FIG. 38, it should be understood that such detection aperture andthe identification tab 83 can also be applied to any one of the first tothe seventh embodiments.

Ninth Embodiment

FIG. 30 is a cross section schematically illustrating the configurationof a disk cartridge according to a ninth embodiment of the presentinvention, and FIG. 31 is a side elevation illustrating a wall in whichthe disk cartridge of FIG. 30 is provided with an opening.

In FIG. 30 and FIG. 31, parts identical or corresponding to those usedin the conventional arrangement shown in FIG. 34 to FIG. 38 aredesignated by the same reference numeral and characters as used before.

Referring to FIG. 30 and FIG. 31, the disk cartridge according to theninth embodiment differs from the conventional arrangement shown in FIG.34 to FIG. 38 only with respect to the projections 91 on the internalsurfaces which define an opening 13, thus reducing the width of theopening 13. The width of the opening 13 is chosen to be substantiallyequal to the thickness of the disk 5 as long as it permits the disk 5 tobe inserted or removed. The disk cartridge thus constructed is capableof preventing the insertion of a foreign matter such as a disk of adifferent type, for example, which may be inserted into the diskcartridge.

FIG. 32 shows a modification of the ninth embodiment in that aprojection 93 is provided only one of the internal surfaces which definethe opening 13.

FIG. 33 shows another modification of the ninth embodiment in thatprojections 94 to 97 are provided at four corners of the internalsurfaces defining the opening 13.

It is to be understood that while the use of the projections has beenillustrated in connection with the conventional arrangement shown inFIG. 34 to FIG. 38, the use of such projections is also applicable toany one of the first to the eighth embodiments.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

What is claimed is:
 1. A disk cartridge comprising: a case including afirst planar portion and a second planar portion which are disposedopposite to each other with a given spacing therebetween, and aplurality of walls which join said first planar portion and said secondplanar portion together, said case containing an information carryingdisk and having an opening formed in one of said plurality of wallsthrough which the disk can be inserted or removed; a lid mounted on saidcase for opening or closing the opening; and a support for supportingsaid lid so said lid is capable of rotating in a plane parallel to saidfirst planar portion and said second planar portion; said lid includinga first projection provided on an inner surface of said lid on a side ofthe first planar portion and a second projection provided on the innersurface of said lid on a side of the second planar portion, therebypermitting an outer periphery of the disk to be fitted between the firstprojection and the second projection when the lid is opened, and holdingthe disk between the first projection and the second projection when thelid is closed, so that the disk is inserted into the case, the innersurface of the lid facing in a direction of insertion of the disk whenthe lid is closed, the first projection and the second projectionprojecting from the inner surface of the lid in a direction of insertionof the disk when the lid is closed.
 2. A disk cartridge comprising: acase including a first planar portion and a second planar portion whichare disposed opposite to each other with a given spacing therebetween,and a plurality of walls which join said first planar portion and saidsecond planar portion together, said case containing an informationcarrying disk, having a first opening through which information transfermay be conducted with said disk and a second opening formed in one ofsaid plurality of walls through which the disk can be inserted orremoved; a lid mounted on said case for opening or closing the secondopening; said second planar portion including a penetration area; anon-replaceable projection being integrally formed as a part of saidfirst planar portion, projecting from an inside of said case and havinga smaller diameter than the penetration area; and said lid including arecess for engaging said projection when said lid is closed and operableto sever said projection when said lid is opened, thereby causing saidprojection to be discharged outside said case through the penetrationarea and causing said first planar portion to be partially deformed; theabsence of said non-replaceable projection establishing the likelihoodof failure of information transfer.
 3. In a disk recording system with acase that may house a disk during information transfer with said disk, amethod of detecting whether said disk case has been opened after initialclosure comprising: a) providing a case having an opening and a coverintended for selective opening by a user to enable removal of said disktherefrom; and b) providing a frangible element as an integral andnon-replaceable part of said case so that said frangible element must bebroken out of said case to open said case after initial closure; c)indicating whether said case has ever been opened after initial closureby the presence of said frangible element in said case; therebyestablishing the likelihood of failure of information transfer.
 4. Themethod of claim 3 wherein the frangible element provided in said step b)is located in a sensor hole.
 5. The method of claim 3 further comprisingsensing the presence of said frangible element within said cartridgewhen said cartridge is inserted into a device intended for reading orwriting data therefrom to determine the likelihood of failure ofinformation transfer.
 6. A disk case for use in housing a disk,including during information transfer, comprising: a first openingenabling information transfer with said disk while in said case; asecond opening allowing selective removal of said disk from said casefor information transfer with said disk without said case; a frangibleelement integrally and non-replaceably provided as part of said case andpositioned to prevent opening of said case after initial closure withoutfirst breaking said frangible element; said frangible element, whenbroken, indicating that said case has been opened to remove said disk;thereby extablishing the likelihood of failure of information transfer.7. The disk case of claim 6 wherein said disk case houses an informationstorage disk to form a disk storage system.
 8. The disk case of claim 6the frangible element is provided in a sensor hole.
 9. The disk case ofclaim of claim 6 wherein the likelihood of failure of informationtransfer is due to possible contamination of said disk.
 10. The methodof claim 5 wherein said step of detecting is performed by an opticalsensor.